Flow Measurement in Sludge Treatment at a Wastewater Treatment Plant in Southern England

A Katronic employee assisted partner Z-Tech in southern England with the commissioning of six KATflow 150 flow meters at a wastewater treatment plant. The project involved measuring the flow rates of activated sludge and excess sludge in 16 gray cast iron pipes. For this purpose, the first Katronic flow meters equipped with Profibus PA modules were supplied in the United Kingdom via ABB. The installation was carried out in compliance with all required spacing and safety regulations, for which Katronic was specifically classified and approved as a “system-critical supplier” for this project.

Monitoring activated sludge and excess sludge is important for maintaining a constant biomass concentration, which is why precise and repeatable flow measurements are of central importance in sludge treatment. The 16 gray cast iron pipes, with diameters ranging from 80 to 440 mm, were installed between 1930 and 1950. Measurements were complicated by sludge deposits inside the pipes, so the portable KATflow 210 and KATflow 230 flow meters were first used to record measurement values during a 24-hour test, which demonstrated the reliability of the measurements.

During the main installation of the six stationary KATflow 150 flow meters, the sensors were each mounted on the pipe approximately 50 m away from the measuring device. Katronic’s “Acoustic Sensor Positioning Assistant” helps determine the correct sensor positioning when the control unit is out of sight but within earshot. For this installation, the Katronic Positioning Assistant from a portable KATflow 200 flow meter was used, which allowed the sensors to be set up on the pipe in advance before they were connected to the main control unit. The Katronic employee also configured the Profibus PA cards in each meter so that they could be successfully connected to the plant’s control system.